Dr Emma Tristram's Judicial Review case showed evidence that due to serious errors and omissions, "something went clearly and radically wrong with the consultation" following which Highways England had decided upon Option 5A as their Preferred Route. This significantly affected the impression given of the relative traffic benefits, and of the relative environmental impacts, of the options. The South Downs National Park Authority also applied successfully for Judicial Review of the decision because it had not properly considered impacts on, or alternative options to reduce impact on, the National Park.

Highways England have responded by announcing that they will undertake a fresh non-statutory consultation in 2019, with more and better information given and with corrections to relevant errors, and with a fully open mind as to what option they will choose in a fresh Preferred Route Announcement. They have paid the legal costs of both Dr Emma Tristram and the National Park Authority.